Device for joining two flexible elements



Dec. 24, 1963 G. DE MESTRAL 7 3,114,951

DEVICE FOR JOINING TWO FLEXIBLE ELEMENTS Filed June 16. 1961 m mwrwe azma 0: Es T H United States Patent Office 3,114,951 Patented Dec. 24, 1963DEVICE FGR JOINING TWG FLEXIBLE ELEMENTS George De Mestral, Commugny,Valid, Switzerland, as-

signor, by mesne assignments, to Velcro S.A., Lenzerheide, Switzerland,a corporation of Switzerland Filed June 16, 1961, Ser. No. 117,639Claims priority, application Switzerland June 23, 1960 1 Claim. (Cl.24-204) Swiss Patents Nos. 295,638 and 399,155 disclose a joining deviceemploying two supports, in this case two sheets of a valvet kind offabric, each of these sheets being provided, on at least one of itsfaces, with a number of booking members. These hooking members may beformed either of loops, or of hooks obtained by cutting a leg of a loop.

.It will readily be understood that by applying two sheets of this kindof fabric one against the other, their hooks and their loops engage onewithin the other, and the two sheets remain hooked. Their separationrequires that a certain force be applied to the two sheets to withdrawthem one from the other. Such hooking or joining devices are designed tobe utilized in particular as closing devices for clothes, curtains orother articles, as a substitute for slide closing devices, buttons andother attachments of this kind, everywhere Where a flexible, invisibleand easily opened closure offers advantages.

The invention relates to a joining device of the kind described in thetwo above mentioned patents, but of simplified construction. The joiningdevice according to the invention comprises two supports in the shape ofstrips provided, on at least one of their faces, with a number ofhooking members, these supports being designed to be applied one againstthe other, the hooking members of one of the supports. being constitutedby loops. This device is characterized by the fact that the hookingmembers of the other support are constituted by hairs folded backtowards the corresponding face of the support.

The invention also has for object a method of manufacture of thisdevice, characterized in that, after having formed a support providedwith standing up hairs, these are subjected to pressure, simultaneouslyto a heat treatment, so as to cause them to fold back against thecorresponding face of the support and to remain fixed in the folded overposition.

The accompanying drawing shows, diagnammatically and by way of exampleseveral embodiments of the joining device according to the invention.

FIG. 1 shows, very diagrammatically a section parallel to the warpthrough an uncut, or velvet, fabric, in the course of manufacture.

FIG. 2 shows a step of the method of manufacture of the joining device.

FIG. 3 shows, in section, how the hooking devices of the two supports ofthe joining device engage one within the other.

FIG. 4 is a plan view of the support showing the hairs folded back.

FIG. 5 shows a modified embodiment of the method of manufacture shown inFIG. 2.

FIG. 6 is a section showing how the hooking members of a joining deviceengage one within the other, according to a modified method ofmanufacture.

FIG. 7 is a plan view of the support with the folded back hairs,according to this modified method.

FIG. 8 is a diagrammatical view in section of another embodiment of thejoining device in the hooking position.

Referring to FIG, 1, the uncut velvet kind of fabric shown ismanufactured by forming a base which comprises several weft threads 1and several warp threads 2.

The hairs 3 of this fabric are formed by means of additional warpthreads 4 which have been passed over metallic bars, not shown, in theshape of spikes. Once they have been passed around these bars, theadditional warp threads 4 constitute loops which are then cut so as toproduce, each one, two hairs 3.

Another method of manufacture of a velvet kind of fabric, of the samekind as that shown in FIG. 1, may also be obtained by weavingsimultaneously two strips each formed of a base comprising several weftthreads 1 and several warp threads 2', additional warp threads beingdisposed, during a same weaving operation, between the two strips, so asto joint the same. Once the weaving of these two strips is finished, itis sufiicient to cut the additional warp threads, disposed substantiallyperpendicular to their base and joining them together, in order toobtain two independent strips of fabric each provided with the hairs 3Preferably, these additional Warp threads 4 are of artificial material,for example themoplastic material, so as to be able to preserve, after aheat treatment, the form which has been given to them. These additionalwarp threads may be either single-ply or multi-ply.

The following step in the method of manufacture of the joining deviceconsists in folding back the locking elements or hairs .3 at an acuteangle relative to the fabric base 1, 2. That is to say, the hairs 3 arefolded back toward the related face of the fabric throughout their fulllength from the point of their emergence from their weft and warpthreads to their tips. This ope-ration may be carried out by applying afiat object 10 against the hairs 3 of the fabric in order to fold themback, for example all of them simultaneously to a same side, as shown inFIG. 2. In order that the hairs 3, once they have been folded back, mayretain their position, the fabric may be subjected, near its base 1, 2,to a heat treatment, for example by means of infra-red ray lamps, bymeans of a vapour jet or a heated air jet directed as shown by thearrows 5 of FIG. 2. Thus, the foot of each of the hairs 3 assumes theshape shown in the drawing and retains the same after cooling andpolymerization of the material forming the hair. In order to increasethe resistance to tearing of the hairs 3 out of the fabric 1, 2, thefabric may be subjected to impregnation, for example with gluingproducts.

When a fabric of the kind shown in FIG. 2, having all hairs 3 foldedback on the same side, is applied against a strip of fabric 6 of theuncut kind provided on one of its faces with a number of small loops 7,the hairs 3 grip the small loops 7 and offer a strong resistance to ashearing or separating force exerted in the direction of the arrows 8and 9 (FIG. 3). In the direction which is the reverse of that of thearrows, the resistance is practically non-existent. As regards theseparation of the fabric 6 from the fabric 1, 2, in a directiontransversal to the latter, the necessary efior-t for such a separationis relatively small. Such a fabric, according to FIG. 2, is thereforeonly applicable under certain particular circumstances, in which theforce to separate the two objects to be joined is always exerted in adefinite direction and by cut-ting.

It is however possible to manufacture a fabric of the kind shown in FIG.2 which offers a higher resistance to separation than the latter in allcutting directions, when it is applied against a fabric of the uncutkind, such as the fabric 6. FIG. 5 shows, as it happens, a modificationof the method of manufacture of the joining device, according to whichthe hairs 3, instead of all being folded back in the same direction, arefolded back in various directions. To that end, it is sufficient toapply a flat object, such as the object 10, against the fabric 1, 2,carrying out if necessary a reciprocating movement, so as to aiiacsiproduce a spreading of the hairs 3 in all directions. Thereafter, theheat treatment applied against the base of the fabric holds the hairs 3in their folded back position. The fabric may then be subjected to animpregnation operation in order to improve the anchoring qualities ofthe hairs 3 in the base of the fabric 1, 2.

FIG. 6 shows how the hairs 3 of the fabric according to this modifiedembodiment engage in the small loops 7 of an uncut fabric 6. It will beseen from this illustration that the joining device will resist theseparation of the two strips of fabric, by cutting, in whateverdirection the cutting efforts are made.

FIG. 7 shows diagrammatically, in plan, how a fabric may present itselfaccording to this embodiment.

PEG. 8 shows another embodiment of the joining device, in which theadditional warp threads 4 forming the hairs 3 are constituted by threadsof thermoplastic material, for example of the nylon kind, provided withnotches 11 forming hooks. These additional warp threads 4 are thereforeformed with these notches 11 before the weaving operation. The presenceof these notches 11 on the folded back hairs 3 appreciably increases theresistance to separation of the hooking device, when these hairs 3engage in the small loops 7 of an uncut fabric 6.

Preferably, this fabric with folded back hairs 3, according to theembodiment shown in FIG. 8, is produced as a result of the sameoperations already described above with reference to FIGS. 2 and inparticular.

Obviously, the notches 11 may have any shape, they may be serrated or inthe shape of cells the edges of which would form two oppositely placedteeth.

As a modification of the embodiment according to FIG. 8, the notches 11could be formed on the standing up hairs after the weaving operation,these standing up hairs 3 being then folded back against the base of thefabric.

In the preceding embodiments, it has always been questioned of formingthe support for the hooking members by a weaving operation. However, itis obvious that one could employ as a support for the hooking membersany strip or plate of plastic material, for example, on which thebooking members would have been applied afterwards by electrostaticdispersion and gluing.

The standing up hairs 3 could also be obtained as one with the plateforming the support by extrusion of plastic material through a screenduring the molding of the supporting plate, so as to form the hairs 3.

I claim:

A fastening device comprising a first pliable support member, aplurality of closed loops operatively connected to said first pliablesupport member, and a second pliable support member, said loopsextending from the plane of its support member towards said secondsupport member, said second pliable support member being woven andincluding a plurality of Weft threads, a plurality of warp threads and aplurality of auxiliary warp threads, said auxiliary warp threads beingin the form of raised pile threads of upstanding straight-lined elementsdirected towards said loops operatively connected to said first pliablesupport member in a plurality of directions each at an acute angle tosaid second support member, said upstanding straight-lined elementsbeing of thermoplastic material, and a plurality of roughened means onsaid upstanding straight-lined elements for ensuring the positiveengagement of said elements with said loops, whereby said plurality ofsaid upstanding straight-lined elements directed in different directionspositively engage said outwardly extending loops of said first supportmember.

References Cited in the file of this patent UNITED STATES PATENTS108,739 Taylor Oct. 25, 1870 1,357,929 Van Heusen Nov. 2, 1920 2,262,881Boenecke Nov. 18, 1941 2,389,565 Taberlet Nov. 20, 1945 2,772,469Staller Dec. 4, 1956 2,806,476 Thompson Sept. 17, 1957 2,820,277 ForsterJan. 21, 1958 2,841,850 Zahorski July 8, 1958 2,976,914 Miller Mar. 28,1961 3,000,384 Piers Sept. 19, 1961 3,020,613 Morin Feb. 13, 19623,031,730 Morin May 1, 1962 FOREIGN PATENTS 183,720 Austria Apr. 15,1955 1,039,964 Germany Oct. 2, 1958 1,064,360 France May 13, 1954

